If you’re making citations in a scientific document and use LaTeX for building it, you might have trouble finding the correct BibTeX-citations. Google Scholar is the tool you need in this case. Here you can search all the literature you might use.
If you have logged in with your google-account, you’ll find a bibliography-manager in the Scholar-preferences. Here you can choose to add links to all found literature that lets you export BibTeX, EndNote or whatever format you need.
Have fun citing!